Students at the Upper Manhattan school say they were subtly coerced to answer surveys with probing psychological questions.

A planned November survey on “negative behavior” was so ethically and racially questionable, teachers and a neighborhood group protested loudly enough to stop it.

The United Federation of Teachers was so perturbed, the union unanimously passed a resolution last month urging the Board of Education to ban such studies.

The board alleges the clinic – run by the Columbia University School of Public Health – never had permission to conduct the November survey in the first place, spokeswoman Margie Feinberg said.

The university, meanwhile, says it’s just trying to help problem students and denies allegations the kids are being used for research projects.

Confusing? Yes.

And disturbing, because the Columbia University School of Public Health – already under fire for being part of an experiment that gave a dangerous diet drug to kids – is once again at the center of a controversy involving kids and psychology.

Stuck in the middle of this morass are about 4,000 mostly Latino and black students.

Take freshman Ulysses Manzon, 15, who recalls taking a so-called “anonymous” questionnaire during class time in September.

He checked “yes” next to the question, “Have you ever thought about killing yourself?”

The next day, a clinic doctor hauls him out of his classroom and into an office for a 45-minute interrogation about his life.

“I felt uncomfortable,” Manzon said. “She was asking me all these questions, and I told her to leave me alone.”

Dozens of students have complained about the intrusive questionnaires freshmen have filled out through the years. A freshman teacher who didn’t want his name used said, “We are all a little suspicious about it.”

Principal Euclid Mejia refused to comment.

The November survey was set up to “target” freshmen students at risk for negative behavior, according to an Oct. 27 memo sent to Mejia. “Those at highest risk will be called down to the clinic for assessment,” the memo stated.

Critics saw the survey as a study on “biodeterminism,” a controversial theory that the genes of minorities – not social influences – determine whether they are violent.

Columbia University Dr. James McCarthy defended the test as a quick way to spot the problems of 1,400 freshmen, but refused to give The Post samples.

Whether the questionnaires were intended for research purposes is unclear.

But teachers, say union leaders, were not “fully informed” of the survey’s purpose, and letters to parents didn’t explain the survey or the possibility that their kids could be hauled out of a classroom for an “assessment.”

McCarthy admits there was a “miscommunication.”

The Columbia clinic and its psychological workings at George Washington should be put under the microscope, because if no one is looking, another kid could end up in one of its experiments.